[GlobalISel] Remove duplicate function using variadic templates. NFC.
[GlobalISel] Remove duplicate function using variadic templates. NFC.

I think the initial version of r293172 was trying:
  std::forward<Args...>(args)...
which doesn't compile.  This seems like the correct way:
  std::forward<Args>(args)...

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@293214 91177308-0d34-0410-b5e6-96231b3b80d8

apple/swift-llvm,llvm-mirror/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,llvm-mirror/llvm,llvm-mirror/llvm,apple/swift-llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,apple/swift-llvm,llvm-mirror/llvm,llvm-mirror/llvm,llvm-mirror/llvm,apple/swift-llvm,GPUOpen-Drivers/llvm,apple/swift-llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm